The temperature method of family planning is reported to show a Pearl Index between I and 2 (G.Doring, 1988). The software of baby comp is created acc. to the rules of the temperature method. We have tested the baby comp to get information about the accepatibility, reliability and accuracy of this contraceptive device.

17 young women have been tested: 5 intended to achieve ( group I ), the others to avoid pregnancy ( group II ). The period of testing was 6 months. The last cycle is monitored by ultrasonic estimation of the growing follicle and by LH-determination in mid-day urine ( Elisa ) to get objective parameters of the fertile phase of the cycle. During all cycles monitoring of the basal body temperature (BBT) and the cervical mucus symptom was performed. It was found, that the temperature registration of the baby comp was correct (p^20,01). After five months the fertile phase of the menstrual cycle was determined correctly in regular cycles. In irregular cycles the number of women studied was too low for final conclusions and has to be increased. Two women in group I (pregnancy wanted) conceived. No woman got pregnant in group II. The acceptability of the device was good. Only one woman wanted to change the method after six months.